Linux Distributions Compared

Been considering installing or re-installing Linux on a PC? Confused by the wide range of distributions available? This article may not solve all your woes, but it should at least put you on the right track.

Value Added

Several vendors are adding value to existing distributions in
various ways. For example, Caldera is adding commercial components
to Red Hat Commercial Linux to create their Caldera Network
Desktop. WorkGroup Solutions used to enhance Slackware as the base
for WGS Linux; they have now switched to basing their work on Red
Hat Commercial Linux. Trans-Ameritech sells disks with several
distributions, including Slackware and Debian; they base their own
value-added work on Slackware, trying to make it easier to
install.

Value-add distributions are worth serious consideration, but
they aren't the subject of this review. As part of deciding which
distribution to get, you may want to consider what you can get from
value-add vendors as well as from the base distributions in
question. Most value-add vendors (as well as distribution vendors)
advertise in Linux Journal.

Binary File Formats

One of the most common sources of confusion in the Linux
world today involves binary file formats (See
What is a binary file format?
sidebar). The Linux community is in a state of transition from the
old “a.out” binary file format to the new “ELF” binary file
format, which has many features that are completely missing in the
a.out format.

ELF is the binary file format used by Unix System V Release
4, but that doesn't mean that a Linux binary in the ELF file format
is compatible with SVR4, nor does it mean that SVR4 binaries can
run on Linux. The capability for Linux to run some SVR3 and SVR4
binaries is provided by the iBCS2 compatibility package, which most
distributions include.

One of ELF's features is extensibility; with ELF, it is
possible for developers to add features that weren't thought of
when the format was first designed. For instance, one Linux
developer has noted that he could add icons to ELF executables
without breaking any software. Icons weren't considered when ELF
was developed, but the format is extensible enough that they can be
easily added.

But perhaps you don't care if you can add an icon to your ELF
binary, or even if anyone else can. What does ELF do for you?
Fundamentally, it makes life much easier for Linux developers. It
also has a few esoteric features which make it practical to support
some software under Linux that was previously impractical to
support. So it gives you more and better software available for
Linux.

Since the whole Linux community is moving to ELF, you don't
want to get stuck with a distribution which does not support ELF. A
year from now, it will be almost impossible to find a.out binaries
for programs you want, and important bug fixes may only be
available for ELF.

Because of this, we have only reviewed distributions which at
least support ELF binaries. The only distributions that are
reviewed here which are not based
on the most current ELF libraries are currently being updated, and
should be based on standard ELF libraries by the time you read
this.

What do we mean by
based?

ELF-based means the entire distribution, or at least, almost
the entire distribution, consists of ELF binaries. a.out binaries
are not provided with the system, or if they are provided, they
aren't part of the “core” of the system or are not available in
ELF format.

By contrast, “supports ELF” means that, while the
distribution is partially or completely built of binaries in the
a.out format, the ELF programming
libraries are included so that ELF binaries will also
run.

Media

Many distributions are available solely on CD-ROM. There are
several reasons for this:

So much software is available for Linux that it is
impractical to provide it all on floppies.

It is much easier to install software from CD-ROM
than to change floppies once a minute.

A cheap supported CD-ROM drive costs approximately
the same as the stack of floppies needed to install a complete
Linux distribution.

However, some distributions (including Debian, Red Hat, and
Slackware) are available via FTP over the Internet in a form
designed to fit on floppies, and Linux System Labs still offers a
floppy distribution service, from which you can order an entire
Linux distribution on floppies, though it is the only company left,
to our knowledge, which does this.

Copyright Considerations

Most distributions are freely available over the Internet,
although only some are actively distributed in a way that makes it
feasible to install them directly from the Internet. You should be
aware that while distributors can restrict you from running
commercial software components on more than one machine, they
cannot restrict you from installing the base Linux software on
multiple machines. A Linux distribution which is packaged in a form
which cannot be installed without installing proprietary software
that is under copyright licensing terms more strict than the GNU
General Public License is probably in violation of copyright law.
[And should be completely avoided, in my strongly held
opinion—ED]

To sum up, you should feel free to install any Linux
distribution you buy on as many machines as you like, as long as
you respect the licensing terms of any proprietary software that is
included with the distribution. Conversely, the vendor needs to
make it possible for you to do so without taking unreasonable
steps.

If you encounter a vendor who makes it difficult or
impossible to install free components without installing
proprietary components that have restrictive licenses, first
politely bring the issue to their attention—they may not have
considered the issue. If the vendor refuses to resolve the issue,
return the distribution, ask for your money back, and send a letter
to the Editor of Linux Journal.